Kai received his Diploma degree in Molecular Biology from the University of Heidelberg and his Ph.D. from the Max Planck Institute of Neurobiology and LMU Munich in Germany. He did his postdoc in Dr. Zena Werb’s lab at the University of California, San Francisco. Kai’s work is focused on how cells communicate and integrate signals from their local microenvironment during normal tissue homeostasis and cancer. His interest in microenvironmental control pathways grew out of his graduate work, where he studied the function of neutrophil serine proteases in acute inflammatory responses (Kessenbrock et al, Journal of Clinical Investigation, 2008) and in the pathogenesis of autoimmune diseases (Kessenbrock et al, Nature Medicine, 2009). During his postdoc he expanded his expertise to the role of matrix metalloproteinases in the tumor microenvironment (Kessenbrock et al, Cell, 2010) and as regulators of breast epithelial stem cells through modulation of the Wnt signaling pathway (Kessenbrock et al, Cell Stem Cell, 2013).

Kai is currently an Associate Professor in the Department of Biological Chemistry at the University of California, Irvine, where he is affiliated with the Chao Family Comprehensive Cancer Center, the UCI Center for Epigenetics and Metabolism and the U54-funded Center for Cancer Systems Biology.  The Kessenbrock Lab uses an interdisciplinary approach combining single-cell genomics, bioinformatics together with functional cellular and molecular biology experiments to understand the role of the microenvironment during breast cancer initiation in unprecedented resolution. They have recently created the first single-cell census the cell types and states within the breast epithelium under normal homeostasis in human (Nat. Commun., 2018) and mouse (Cell Reports, 2020), which has started to serve as a reference to delineate how the breast microenvironment goes awry during breast cancer, for example through the emergence of immunosuppressive myeloid cells (Science Immunology, 2020) as well as during precancerous changes in the human breast microenvironment of germline BRCA1 mutation carriers (Nature Genetics, 2023). Kai is co-leader of the multi-institutional Human Breast Cell Atlas (funded by a Chan/Zuckerberg Initiative Seed Network), where we have generated a comprehensive spatially resolved atlas of the human breast (Nature, 2023), which will serve as a reference to map out cellular changes occurring during breast cancer initiation and progression.